1 files changed, 91 insertions, 0 deletions
diff --git a/web/global/hashStorage.go b/web/global/hashStorage.go
new file mode 100644
index 00000000..099a54ed
--- /dev/null
+++ b/web/global/hashStorage.go
@@ -0,0 +1,91 @@
+package global
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"sync"
+	"time"
+)
+
+type HashEntry struct {
+	Hash      string
+	Value     string
+	Timestamp time.Time
+}
+
+type HashStorage struct {
+	sync.RWMutex
+	Data       map[string]HashEntry
+	Expiration time.Duration
+	ForceSave  bool
+}
+
+func NewHashStorage(expiration time.Duration, forceSave bool) *HashStorage {
+	return &HashStorage{
+		Data:       make(map[string]HashEntry),
+		Expiration: expiration,
+		ForceSave:  forceSave,
+	}
+}
+
+func (h *HashStorage) AddHash(query string) string {
+	if h.ForceSave {
+		return h.saveValue(query)
+	}
+
+	// we only need to hash for more than 64 chars by default
+	if len(query) <= 64 {
+		return query
+	}
+
+	return h.saveValue(query)
+}
+
+func (h *HashStorage) saveValue(query string) string {
+	h.Lock()
+	defer h.Unlock()
+
+	md5Hash := md5.Sum([]byte(query))
+	md5HashString := hex.EncodeToString(md5Hash[:])
+
+	entry := HashEntry{
+		Hash:      md5HashString,
+		Value:     query,
+		Timestamp: time.Now(),
+	}
+
+	h.Data[md5HashString] = entry
+
+	return md5HashString
+}
+
+func (h *HashStorage) GetValue(hash string) string {
+	h.RLock()
+	defer h.RUnlock()
+
+	entry, exists := h.Data[hash]
+	if !exists {
+		return hash
+	}
+	return entry.Value
+}
+
+func (h *HashStorage) RemoveExpiredHashes() {
+	h.Lock()
+	defer h.Unlock()
+
+	now := time.Now()
+
+	for hash, entry := range h.Data {
+		if now.Sub(entry.Timestamp) > h.Expiration {
+			delete(h.Data, hash)
+		}
+	}
+}
+
+func (h *HashStorage) Reset() {
+	h.Lock()
+	defer h.Unlock()
+
+	h.Data = make(map[string]HashEntry)
+}